Lesson 3.5: Measurement – Mass & Time | SEA Mathematics | My Carib Academy
SEA 2025-2028 Framework Aligned

⚖️ Lesson 3.5: Measurement – Mass & Time

Master measuring mass (g, kg) conversions, word problems, telling time, duration & time word problems. This lesson covers SEA Mathematics Objectives 163-178 from the Measurement Strand.

75 Minutes
Module 3: Measurement
Objectives 163-178
3 Videos
Lesson Progress 0%

Previous Lesson

Did you complete Lesson 3.4? Review Volume & Capacity →

Learning Objectives

By the end of this lesson, you will be able to:

  • Convert between grams and kilograms (Objectives 163-165)
  • Solve mass word problems involving conversions (Objectives 166-169)
  • Read and tell time on analog and digital clocks (Objectives 170-172)
  • Calculate duration between two times (Objectives 173-175)
  • Solve time word problems (Objectives 176-178)

SEA Tip

Mass and time questions appear in Section I, II, and III of the SEA Math paper. These are practical life skills! (SEA Framework Page 25-26)

Watch: Measuring Mass (g, kg Conversions)

Start by watching this video to learn about mass conversions. Take notes as you watch! 📝

Measuring Mass: g, kg Conversions – Mathematics Video Lesson

Quick Check

Did you understand the video? Review the notes below before continuing! ✅

Measuring Mass: Grams & Kilograms

Mass is how heavy something is. We measure mass in grams (g) and kilograms (kg)!

Mass Conversions

  • 1 kilogram (kg) = 1000 grams (g)
  • 1 gram (g) = 0.001 kilogram (kg)
  • ½ kg = 500 g
  • ¼ kg = 250 g

📊 Conversion Table:

From To Multiply/Divide Example
kg → g Multiply by 1000 × 1000 2 kg = 2000 g
g → kg Divide by 1000 ÷ 1000 500 g = 0.5 kg

📊 Example 1: Converting Mass

Convert 3.5 kg to grams

Solution:

  1. Identify: kg → g (multiply by 1000)
  2. Calculate: 3.5 × 1000 = 3500
  3. Answer: 3500 g

Answer: 3500 g

📊 Example 2: Mass Word Problem

Shopping for Rice

Question: A bag of rice weighs 5 kg. Another bag weighs 3500 g. What is the total mass in kg?

Solution:

  1. Convert to same unit: 3500 g = 3.5 kg
  2. Add: 5 kg + 3.5 kg = 8.5 kg

Answer: 8.5 kg

Memory Trick

kg to g: Multiply by 1000 (add 3 zeros)
g to kg: Divide by 1000 (move decimal 3 places left)
Think: Kilo means 1000!

Watch: Mass Word Problems

Now watch this video to learn how to solve mass word problems. Pay attention! 🎯

Mass Word Problems – Mathematics Video Lesson

Watch: Telling Time, Duration & Time Word Problems

Watch this video to learn about telling time and calculating duration. 🎯

Telling Time, Duration & Time Word Problems – Mathematics Video Lesson

Telling Time & Duration

Time tells us when something happens. Duration tells us how long something takes!

📋 Time Conversions:

Time Units

  • 1 hour = 60 minutes
  • 1 minute = 60 seconds
  • 1 day = 24 hours
  • ½ hour = 30 minutes
  • ¼ hour = 15 minutes

📊 Example 3: Telling Time

3:00

Hour hand (short) = 3, Minute hand (long) = 12

📊 Example 4: Calculating Duration

Finding Duration Between Two Times

Question: A movie starts at 2:30 PM and ends at 4:15 PM. How long is the movie?

Solution:

  1. From 2:30 to 3:30: 1 hour
  2. From 3:30 to 4:15: 45 minutes
  3. Total: 1 hour 45 minutes

Answer: 1 hour 45 minutes

📊 Example 5: Time Word Problem

Bus Journey Time

Question: A bus leaves Port of Spain at 8:45 AM and arrives in San Fernando at 10:20 AM. How long was the journey?

Solution:

  1. From 8:45 to 9:45: 1 hour
  2. From 9:45 to 10:20: 35 minutes
  3. Total: 1 hour 35 minutes

Answer: 1 hour 35 minutes

Common Mistake

Don’t forget: 60 minutes = 1 hour! When subtracting times, borrow 60 minutes (not 100) if needed.

Quick Quiz

Test your understanding! Select an answer for each question. ⚖️

6 Questions
12 Minutes
70% to Pass

1. How many grams are in 2 kilograms?

2. Convert 3500 g to kg

3. How many minutes are in 2 hours?

4. A movie starts at 3:00 PM and ends at 4:30 PM. How long is it?

5. What is ½ kg in grams?

6. A bus journey takes 1 hour 45 minutes. How many minutes is this?

0/6

Lesson Complete!

Great job finishing Lesson 3.5! You’re mastering mass and time for the SEA exam! 🎉

Back to SEA Maths